Propulsion of wheels on vehicles has been accomplished in many ways, including, pedal means for unicycles, bicycles, tricycles and motorized means such as those used in motorcycles. In the field of pedal driven vehicles, the unicycle, while providing ease of propulsion, has the serious steering and balancing disadvantage. The tricycle solved the steering and balance problem, but has a rear loading disadvantage that detracts from the combined front end steering and propulsion advantage. The bicycle has provided a compromise solution to the steering and propulsion problem by including a chain and sprocket drive system that propels the rear wheel of the vehicle in conjunction with a handle bar steerable front wheel that results in much more effective propulsion than the unicycle or the tricycle. In an analog manner, the front wheel is a follower of a pedal driven rear wheel.
The bicycle and tricycle have been mimicked in motorized version that enhance the manner of propulsion. The bicycle and its motorized motorcycle equivalent have the common feature whereby the front wheel is non-driven, i.e. the rear wheel is propelled by either the pedals or motor, via a chain and sprocket system. Both suffer in forward propulsion efficiency due to the loading-down effects of the non-driven front wheel under rough, off-road and incline types of riding and driving conditions. In four wheel vehicles, similar inefficiencies have been compensated for by providing a front wheel drive system that propels the vehicle through rough terrain conditions. The systems used by four wheel vehicles are selectable front wheel gear drive systems or factory provided front wheel transmissions. For bicycles, the power deficiency problems have resulted in solutions directed at making the bicycle lighter, adding a wide range of gear ratio drive systems or adding a bike frame and steering structure that complements a rider's power pedaling stance required during rough terrain riding applications.
Prior art patents that teach front wheel drive for bicycles include U.S. Pat. No. 4,773,662, which provides a double-drive system whereby an operator engages a handle bar arm operated chain and sprocket drive system for the front wheel of a bicycle. The '662 apparatus would prove difficult to operate under conditions requiring rear and front power stroke along with directional steering. Further, the arm pedaling effectiveness is questionable under rough terrain or soft soil surfaces. U.S. Pat. No. 3,948,542 provides a solution for a need of additional forward propulsion in the rear wheels of a bicycle in the form of a system having gears, chain and sprockets that operate by movable action of the seat member of a bicycle. U.S. Pat. No. 1,796,682 teaches a pedal and seat driven exercise vehicle having a belt and gear system for translating the steering motion to a front wheel. U.S. Pat. No. 2,232,908 teaches a perambulator embodying means under the control of a rider whereby the front end or rear end, or both may be caused to undulate as the vehicle moves along.
In present bicycle applications, the mountain bike has gained wide popularity for its design that enables a rider to propel over rough terrain very efficiently, mainly due to the low gearing (typically 12 to 30-tooth rear cog, compared to 32-52 tooth rear cog for road bikes), the light weight, the flat handle bars and wider tires. While the above feature allow a rider to engage in the off-road sport, there are some riding conditions where a distributed application of wheel propulsion power, i.e. a combination rear and front propulsion, would prove most advantageous. Similarly advantage is seen in a cross-country motor bike. The presently known drive systems for driving or propelling a bicycle or motorcycle do not provide a solution for the controlled distributed application of the wheel propulsion power between the front non-driven wheel and rear driven wheel.
Thus, a need is seen to exist for a power transfer apparatus that is controllably actuated to distribute rotary power between a normally driven wheel and a non-driven wheel.
A need is further seen to exist for a power transfer apparatus in kit form to fit either bicycles or motorcycles and that is controllably actuated to distribute rotary power between a normally driven wheel and a non-driven wheel.
A need is also seen to exist for a bicycle apparatus and a motorcycle apparatus having a factory provided power transfer apparatus that is controllably actuated to distribute rotary power between a normally driven wheel and a non-driven wheel.